smallchungus · smallchungus · Apr 18, 2026 · Apr 18, 2026 · Apr 18, 2026
diff --git a/docker-compose.yaml b/docker-compose.yaml
@@ -27,6 +27,11 @@ services:
       timeout: 2s
       retries: 10
 
+  gotenberg:
+    image: gotenberg/gotenberg:8
+    ports:
+      - "3000:3000"
+
   api:
     build:
       context: .

diff --git a/internal/pdf/client.go b/internal/pdf/client.go
@@ -0,0 +1,59 @@
+package pdf
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"time"
+)
+
+type Client struct {
+	endpoint string
+	http     *http.Client
+}
+
+func New(endpoint string) *Client {
+	return &Client{endpoint: endpoint, http: &http.Client{Timeout: 60 * time.Second}}
+}
+
+func (c *Client) RenderHTML(ctx context.Context, html []byte) ([]byte, error) {
+	body := &bytes.Buffer{}
+	w := multipart.NewWriter(body)
+
+	part, err := w.CreateFormFile("files", "index.html")
+	if err != nil {
+		return nil, fmt.Errorf("form file: %w", err)
+	}
+	if _, err := part.Write(html); err != nil {
+		return nil, fmt.Errorf("write html: %w", err)
+	}
+	if err := w.Close(); err != nil {
+		return nil, fmt.Errorf("close writer: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.endpoint+"/forms/chromium/convert/html", body)
+	if err != nil {
+		return nil, fmt.Errorf("new request: %w", err)
+	}
+	req.Header.Set("Content-Type", w.FormDataContentType())
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("post: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode/100 != 2 {
+		errBody, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("gotenberg %d: %s", resp.StatusCode, string(errBody))
+	}
+
+	pdf, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read body: %w", err)
+	}
+	return pdf, nil
+}
diff --git a/internal/pdf/client_integration_test.go b/internal/pdf/client_integration_test.go
@@ -0,0 +1,72 @@
+//go:build integration
+
+package pdf_test
+
+import (
+	"context"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/smallchungus/disttaskqueue/internal/pdf"
+)
+
+func TestRenderHTML_PostsMultipartAndReturnsPDF(t *testing.T) {
+	const fakePDF = "%PDF-1.7\nfake\n%%EOF"
+	var gotForm map[string]string
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/forms/chromium/convert/html" {
+			t.Errorf("path: %s", r.URL.Path)
+		}
+		_, params, err := mime.ParseMediaType(r.Header.Get("Content-Type"))
+		if err != nil {
+			t.Fatalf("ct: %v", err)
+		}
+		mr := multipart.NewReader(r.Body, params["boundary"])
+		gotForm = map[string]string{}
+		for {
+			p, err := mr.NextPart()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			b, _ := io.ReadAll(p)
+			gotForm[p.FileName()] = string(b)
+		}
+		w.Header().Set("Content-Type", "application/pdf")
+		_, _ = w.Write([]byte(fakePDF))
+	}))
+	defer srv.Close()
+
+	c := pdf.New(srv.URL)
+	got, err := c.RenderHTML(context.Background(), []byte("<html><body>hi</body></html>"))
+	if err != nil {
+		t.Fatalf("render: %v", err)
+	}
+	if string(got) != fakePDF {
+		t.Fatalf("got %q, want %q", got, fakePDF)
+	}
+	if v := gotForm["index.html"]; v != "<html><body>hi</body></html>" {
+		t.Fatalf("index.html: %q", v)
+	}
+}
+
+func TestRenderHTML_ReturnsErrorOnNon2xx(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusBadRequest)
+		_, _ = w.Write([]byte("bad html"))
+	}))
+	defer srv.Close()
+
+	c := pdf.New(srv.URL)
+	_, err := c.RenderHTML(context.Background(), []byte("garbage"))
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}